46
5-1
On-screen Switch Inputs
The DT-type PT
can transmit to the host the status of touch switches set on
screens. A maximum of 64 switches can be set per screen. The DN-type can
transmit to the host the inputs of 12-key Function Key Units and External I/O
Units.
5-1-1
Transmitting to the Host
There are two ways to transmit the status of switches to the host. These
methods are described briefly below. For more detail, refer to the Host Inter-
face Unit Operation Manual.
Switch-Number Method
When a switch is pressed, the number corresponding to that switch is trans-
mitted to the host as a numeric value in three digits of BCD. When two
switches are pressed, the first one is given priority in transmission. When
using an NT600M-LK201 or NT600M-RT121/LB121 Host Interface Unit, send
the data to the host by means of the strobe signal in the PT status informa-
tion which is output when switches are pressed.
Bit-Switch Method
The status of each switch is transmitted to the host as a bit status. This is the
method used when substituting for ordinary operating switches. You can use
it for ordinary bit input switches from a Programmable Controller. In order to
use this method, you must set “bit input” in advance at the Support Tool or
use the Host Link Interface direct connection function.
Note With this method, it is possible to push a number of switches simultaneously
as long as they are in the same vertical row or the same horizontal column.
Do not simultaneously press switches that are in both different rows and in
different columns. At the right in the following example, simultaneously press-
ing switches A, B, and D will automatically turn switch C to ON.
Switch B
Switch C
:Switches pushed down
Okay
No
Switch D
Switch A
For details, refer to the Host Interface Unit Operation Manual.
5-1-2
Creating Touch Switches (DT Type Only)
Just as with lamps, touch switches are created and registered with the Sup-
port Tool. The setting content is as follows:
Frame Display
Standard/Cubic Type/Without
Inversion at input time
With/Without
Guide character
With/Without
Setting Parameters
Combine your choices of rectangular sections from the among the 72 blocks
shown in the diagram below, and designate them as switches. Switches must
be set in increments of these blocks.
Number of Settings
You can set a maximum total of 64 switches per screen. If you wish, the
whole screen can also be set as one input switch.
On-screen Switch Inputs
Section 5-1
